WO2016166037A1

WO2016166037A1 - Carpet coating compositions

Info

Publication number: WO2016166037A1
Application number: PCT/EP2016/057861
Authority: WO
Inventors: Timo MELCHIN; Holger KÜNSTLE; Doris PFINGSTL; Robert Tangelder
Original assignee: Wacker Chemie Ag
Priority date: 2015-04-17
Filing date: 2016-04-08
Publication date: 2016-10-20
Also published as: CN107532032B; DE102015206954A1; CN107532032A; US10480122B2; EP3283568A1; US20180135242A1; EP3283568B1

Abstract

The invention relates to the use of mixtures that contain an aqueous dispersion of a vinyl acetate polymer and an aqueous dispersion of a vinyl acetate-ethylene copolymer for carpet coating compositions, and corresponding carpet coating compositions, as well as carpets which are coated with such carpet coating compositions.

Description

Carpet coating compositions

The invention relates to the use of mixtures comprising an aqueous dispersion of a vinyl acetate polymer and an aqueous dispersion of a vinyl acetate-ethylene copolymer for carpet coating compositions, corresponding carpet coating compositions and carpets which are coated with such carpet coating compositions are. In the production of typical, commercially available carpets, for example, sheet or carpet tile, the carpet pile is formed from tufts, which are, for example, looped into a woven or laid primary backing material in the form of loops. The loops are only loosely connected to the flat carrier material (tufted carpet) and are therefore treated to stabilize the raw carpet with a binder-containing formulation. This is foamed or unfoamed applied to the back of the support material (precoat or precoat) and typically contains fillers, such as chalk, and optionally further additives, such as thickeners, dispersing agents or foam auxiliaries, in addition to an aqueous polymer dispersion.

The carpet products obtained in this way can be equipped with another backing material (backing, secondary backing) to improve the dimensional stability. It is generally a fabric of synthetic fiber such as polypropylene, polyamide or polyester, or natural fiber such as jute. To connect the carpet backing to the carpet obtained after the pre-coat, a binder is applied again, which may be formulated similarly to the coating composition of the pre-coat. In this second coating as well, the abovementioned aqueous polymer dispersions, in the form of foam or unfoamed, can be applied with fillers and further additives, such as thickeners, dispersing aids or foam auxiliaries (second-line or secondary coating). WO 90/00967 A1 describes the use of aqueous dispersions of vinyl acetate-ethylene copolymers, styrene-butadiene copolymers or styrene-acrylate copolymers instead of PVC plastisol as binders in carpet production. US Pat. No. 3,779,799 describes the production of a tufted carpet using, as precursor, binder compositions comprising as binder vinyl acetate-ethylene copolymer dispersions (VAE copolymer dispersion), polyethylene dispersions or dispersions of carboxylated styrene -Butadiene copolymers. In US 4,239,563 aqueous vinyl acetate-ethylene copolymer dispersions are described as binders for the consolidation of carpets. Compared with styrene-butadiene latices, the lower emission of VOCs (volatile organic compounds) is emphasized. The patent US Pat. No. 4,735,986 describes as a carpet binder a composition comprising a vinyl acetate-ethylene copolymer dispersion which contains a stabilizer mixture of partially hydrolyzed PVOH, fully hydrolyzed PVOH and a nonionic, polyalkoxylated emulsifier. US Pat. No. 5,026,765 describes carpet coating compositions based on vinyl acetate-ethylene copolymer dispersions, the copolymers also containing monomer units whose homopolymers have glass transition temperatures Tg of at least 50 ° C. GB patent GB 1,298,155 describes carpet-coating compositions based on aqueous, crosslinkable binders containing vinyl acetate-ethylene copolymers, polyvinyl alcohol (PVOH) and glyoxal.

WO 2010/089142 A1 discloses a vinyl acetate-ethylene copolymer dispersion which is used as a binder in carpet production. The copolymer contains 1 to 4 wt .-% of ethylene and is stabilized exclusively with emulsifier, wherein optionally small amounts of protective colloid can be used for stabilization. For comparison, a vinyl acetate homopolymer was tested as a binder. This resulted in carpets with too high rigidity and unsatisfactory 180 ° fracture behavior. In order to improve the adhesion to polyvinyl butyral film (as backing), WO 2006/007157 A1 proposes the use of vinyl acetate-ethylene copolymers, which contain 1 to 10 wt .-% of comonomer units having functional groups, such as carboxyl, amide, N-methylol or hydroxyalkyl groups. In the preparation of the copolymer, a mixture of emulsifier and 0.05 to 4 wt .-% protective colloid is used. In US Pat. No. 6,359,076, in order to improve the water resistance of carpet coatings, it is proposed to use crosslinkable vinyl acetate-ethylene copolymers containing OH-functional monomer units in combination with a crosslinker. WO 2011/139267 A1 and WO 2011/140065 A2 teach carpet coatings based on vinyl acetate-ethylene copolymers, the functional, crosslinkable corona monomer units, such as silane-functional or multifunctional corona monomers, and stabilizing no protective colloids but contain emulsifiers. From WO 2012/020319 A2 or WO 2012/020321 A2 carpets are known, which are characterized by good flame resistance or good washability. As binders, vinyl acetate

Ethylene copolymer dispersions having average particle sizes dw of 50 to 500 nm used, which were adjusted by polymerization with stabilization with emulsifier, wherein optionally up to 3% protective colloid can be used as a costabilizer. The subject of WO 2013/093547 A2 are carpet binders whose composition is optimized for formulations with carbon black as filler. The binders used are emulsifier and cellulose ether-stabilized vinyl acetate-ethylene copolymer dispersions. WO 2013/123210 AI relates to carpets, for the production of binder mixtures of vinyl acetate-ethylene copolymer dispersions and styrene-butadiene copolymer dispersions were used. To improve the compatibility of the various polymer dispersions, it is proposed to use polyvinyl alcohol in the VAE dispersion and to use at most up to 1.5% by weight of polyvinyl alcohol, based on the comonomers, as the protective colloid in their preparation. WO 2014/031579 A2 relates to carpet coating compositions which, as binders, may contain inter alia VAE dispersions which are stabilized with emulsifier and optionally also contain up to 1.5% by weight of polyvinyl alcohol as co-stabilizer can. These dispersions are mixed with an alpha-olefin-carboxylic acid copolymer and a crosslinker.

There is a need to further develop the properties of vinyl acetate-ethylene-based binders for formulating performance-balanced carpet coating compounds. One attempt here was the binder mixtures already mentioned in WO 2013/123210 Al based on vinyl acetate-ethylene copolymer dispersions and styrene-butadiene copolymer dispersions. Such mixtures are characterized by high Noppenauszugwerten in the binder mixtures used.

However, the vinyl acetate-ethylene copolymer dispersion always contains an emulsifier, which adversely affects the filler compatibility and the mechanical strength, in particular the separation strengths. On the other hand, pure protective colloid-stabilized vinyl acetate-ethylene copolymer dispersions, for example with partially hydrolysed polyvinyl alcohol or modified and / or unmodified celluloses, have good filler compatibilities and high mechanical strengths, but are generally less compatible with styrene-butadiene copolymer dispersions and tend in mixtures without the use of special emulsifiers and / or high dilution to dramatic viscosity increases or coagulation.

Although the use of vinyl acetate-ethylene copolymers as binders in carpet backings makes it possible to adjust the strength of the final carpet by controlling the glass transition temperature of the polymer, certain settings nevertheless remain inaccessible. Particularly high strengths are difficult to access and the adaptation of the binder to the requirements of the final product with wide variation in strength would lead to a commercially unattractive variety of products. There is therefore a need for a product which makes it possible to adjust the strengths in the finished carpet with mixed-stabilized (emulsifier and protective colloid) or purely protective colloid-stabilized vinyl acetate-ethylene copolymers, without the need for plasticizers or film-forming aids, and the mechanical strengths of the Vinyl acetate-ethylene copolymer-containing binder in the carpet backing improved.

Surprisingly, it was possible to meet the requirement profile through the use of mixtures of vinyl acetate-ethylene copolymer dispersions and vinyl acetate homopolymer dispersions, with surprising synergistic reinforcing effects with respect to the dimpled separation force and separation resistance compared to the dispersions not used as a mixture. The coating composition compositions surprisingly and unexpectedly make it possible to set specific strengths of the finished carpet at high separation strengths and high nap removal forces.

The invention relates to the use of mixtures comprising an aqueous dispersion of a vinyl acetate polymer and an aqueous dispersion of a vinyl acetate-ethylene copolymer for carpet coating compositions.

The vinyl acetate polymer is obtained by free-radically initiated emulsion polymerization in an aqueous medium of from 99 to 100% by weight of vinyl acetate and optionally up to 1% by weight of further comonomers, in each case based on the total weight of the monomers. The weights in% by weight for the comonomers add up to 100% by weight in each case. The vinyl acetate polymer preferably contains no ethylen units. With particular preference, no further comonomers are polymerized in addition to vinyl acetate.

The vinyl acetate-ethylene copolymer is prepared by means of free-radically initiated emulsion polymerization in an aqueous medium of 65 to 98% by weight of vinyl acetate and 2 to 30% by weight of ethylene, preferably 75 to 95% by weight of vinyl acetate and 5 to 25% by weight. % Of ethylene, based in each case on the total weight of the monomers. Optionally, up to 10 wt .-%, preferably 0.1 to 10 wt .-%, in each case based on the total weight of the monomers, even more comonomers are copolymerized copo. Particularly preferred are no further Comono mers copolymerized. The data in% by weight for the comonomers add up to 100% by weight in each case.

Suitable further comonomers for the vinyl acetate polymer or the vinyl acetate-ethylene copolymer are in each case those from the group of vinyl esters having 3 to 12 C atoms in the carboxylic acid radical such as vinyl propionate, vinyl laurate, vinyl esters of alpha-branched carboxylic acids having 8 to 11 C -Atomen such as VeoVa ^R EH, VeoVa ^R 9 or VeoVa ^R 10 (trade name of the company Resolution). Also suitable are methacrylic esters or acrylic esters of unbranched or branched alcohols having 1 to 15 C atoms, such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, norbornyl acrylate. Also suitable are vinyl halides such as vinyl chloride.

Other suitable comonomers are also ethylenically unsaturated mono- and dicarboxylic acids, preferably acrylic acid, methacrylic acid, fumaric acid and maleic acid; ethylenically unsaturated carboxylic acid amides and nitriles, preferably acrylamide and acrylonitrile; Mono- and diesters of fumaric acid and maleic acid, such as diethyl and diisopropyl esters, and also maleic anhydride, ethylenically unsaturated sulfonic acids or their salts, preferably vinylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid. Further examples are precrosslinking comonomers, such as polyethylenically unsaturated comonomers, for example diene vinyl adipate, diallyl maleate, allyl methacrylate or triallyl cyanurate, or postcrosslinking comonomers, for example acrylamidoglycolic acid (AGA), methyl acrylamidoglycolic acid methyl ester (MAGME), N-methylol acrylamide (NMA), N-methylol methacrylamide ( NMMA), N-methylolallyl carbamate, alkyl ethers such as the isobutoxy ether or esters of N-methylolacrylamide, of N-methylolmethacrylamide and of N-methylolallyl carbamate. Also suitable are monomers having hydroxyl or carboxyl groups, such as, for example, methacrylic acid and hydroxyalkyl acrylates, such as hydroxyethyl, hydroxypropyl or hydroxybutyl acrylate or methacrylate, and also 1,3-dicarbonyl compounds, such as acetoacetoxyethyl acrylate, acetoacetoxypropyl methacrylate, acetoacetoxyethyl methacrylate. rylate, acetoacetoxybutyl methacrylate, 2, 3-di (acetoacetoxy) propyl methacrylate and allyl acetoacetate.

Other suitable comonomers are epoxide-functional comonomers such as glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether, vinyl glycidyl ether. Further examples of suitable further comonomers are silicon-functional comonomers, such as acryloxypropyltri (alkoxy) and methacryloxypropyltri (alkoxy) silanes, vinyltrialkoxysilanes and vinylmethyldialkoxysilanes, preferably having alkyl or alkoxy groups each having 1 to 2 C atoms, for example, vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane.

The monomer is selected such that the vinyl acetate polymer generally has a glass transition temperature Tg of + 25 ° C to + 40 ° C and the vinyl acetate-ethylene copolymer generally has a glass transition temperature Tg of -20 ° C to + 20 ° C. , The glass transition temperature Tg of the polymers can be determined in a known manner by means of DSC (Dynamic Differential Thermal Analysis, DIN EN ISO 11357-1 / 2). The Tg can also be approximated using the Fox equation. After Fox T.G., Bull. Am. Physics Soc. 1, 3, page 123 (1956): 1 / Tg = xl / Tgl + x2 / Tg2 + ... + xn / Tgn, where xn represents the mass fraction (wt .-% / 100) of the monomer n, and Tgn is the glass transition temperature in Kelvin of the homopolymer of the monomer n. Tg values for homopolymers are listed in Polymer Handbook 2nd Edition, J. Wiley & Sons, New York (1975).

The preparation of the vinyl acetate polymer or of the vinyl acetate-ethylene copolymer is carried out in each case in a known manner, preferably by means of free-radically initiated emulsion polymerization in water. In this case, the aqueous dispersion of the vinyl acetate polymer and the aqueous dispersion of the vinyl acetate-ethylene polymer are each prepared in separate polymerization. The polymerization temperature is 40 ° C to 120 ° C, preferably 60 ° C to 90 ° C, respectively. In the copolymerization of gaseous comonomers, such as ethylene, is preferably under pressure, generally between 5 bar and 120 bar, worked. The initiation of the polymerization can be carried out using the initiators customary for emulsion polymerization, such as hydroperoxide or t-butyl hydroperoxide, or redox initiator combinations, with reducing agents, such as (iso) ascorbic acid or Na-hydroxymethanesulfinate (Brüggolit FF), respectively. To control the molecular weight, regulating substances can be used during the polymerization.

The polymerization of the vinyl acetate polymer takes place in the presence of protective colloid, optionally in combination with emulsifier. The polymerization of the vinyl acetate-ethylene copolymer takes place in the presence of protective colloid or in the presence of emulsifier or in the presence of a combination of protective colloid and emulsifier.

Protective colloids customary for stabilizing the polymerization batch are, for example, partially hydrolyzed or fully saponified polyvinyl alcohols; polyvinylpyrrolidones; polyvinyl; Polysaccharides in water-soluble form, such as starches, celluloses or their derivatives, such as carboxymethyl, methyl, hydroxyethyl, hydroxypropyl derivatives; Proteins such as casein or caseinate, soy protein, gelatin; Lignin sulphonates; synthetic polymers such as poly (meth) acrylic acid, copolymers of (meth) acrylates with carboxyl-functional comonomer units, poly (meth) acrylamide, polyvinylsulfonic acids and their water-soluble copolymers; Melamine formaldehyde sulfonates, naphthalene formaldehyde sulfonates, styrene maleic acid and vinyl ether maleic acid copolymers. Preference is given to celluloses or their derivatives, or partially saponified

Polyvinyl alcohols having a degree of hydrolysis of 80 to 95 mol% and a Höppler viscosity in 4% aqueous solution of 1 to 40 mPas, in particular 3 to 30 mPas (method according to Hoppler at 20 ° C, DIN

53015). Particularly preferred are partially hydrolyzed, low molecular weight polyvinyl alcohols having a degree of hydrolysis of preferably 80 in each case to 95 mol%, more preferably 85 to 90 mol%, most preferably 87 to 89 mol%, and a Hoppler viscosity of preferably 1 to 5 mPas and more preferably 2 to 4 mPas (determined according to DIN 53015, Method according to Hoppler, at 20 ° C, in 4% aqueous solution).

If appropriate, it is also possible to use partially hydrolysed, relatively high molecular weight polyvinyl alcohols having a degree of hydrolysis of preferably 80 to 95 mol% and a Höppler viscosity in 4% strength aqueous solution of preferably> 5 to 40 mPas, particularly preferably 8 to 40 mPas (Method according to Hoppler at 20 ° C., DIN 53015) in admixture with the partially hydrolyzed, low molecular weight polyvinyl alcohols. Optionally, fully hydrolyzed, relatively high molecular weight polyvinyl alcohols having a degree of hydrolysis of preferably 96 to 100 mol%, in particular 98 to 100 mol%, and a Höppler viscosity in 4% aqueous solution of preferably 10 to 56 mPas (method Höppler at 20 ° C, DIN 53015) are used in admixture with the partially hydrolyzed, low molecular weight polyvinyl alcohols. The partially hydrolyzed, relatively high molecular weight polyvinyl alcohols and / or the fully hydrolyzed, relatively high molecular weight polyvinyl alcohols are each used in an amount of from 0.1 to 4% by weight, based in each case on the total weight of the comonomer.

Also preferred are modified polyvinyl alcohols, also referred to below as X-PVOH, having a degree of hydrolysis of from 80 to 99.9 mol%, preferably from 85 to 95 mol%, and a Höppler viscosity, in 4% strength aqueous solution of 1 up to 30 mPas (determined according to DIN 53015 at 20 ° C). Examples of these are polyvinyl alcohols carrying functional groups, such as acetoacetyl groups. Also preferred are ethylene-containing polyvinyl alcohols, so-called E-PVOH, which are known, for example, under the trade name EXCEVAL®. E-PVOH are partially or preferably fully hydrolyzed copolymers of vinyl acetate and ethylene. Preferred E-PVOH have an ethylene content of 0.1 to 12 mol%, preferably 1 to 7 mol%, particularly preferably 2 to 6 mol% and in particular 2 to 4 mol%. The mass-average degree of polymerization carries from 500 to 5000, preferably from 2000 to 4500 and more preferably from 3000 to 4000. The degree of hydrolysis is generally greater than 92 mol%, preferably from 94.5 to 99.9 mol% and particularly preferably from 98.1 to 99.5 mol -%.

The protective colloids are commercially available and accessible by methods known to those skilled in the art. It is also possible to use mixtures of the protective colloids mentioned. The polymerization preferably takes place in the presence of a total of from 2 to 10% by weight of protective colloid, particularly preferably in total from 5 to 10% by weight, in each case based on the total weight of the monomers.

To stabilize the dispersion, preference is given to using nonionic emulsifiers. It is also possible to use ionic, preferably anionic, emulsifiers. It is also possible to use combinations of nonionic emulsifiers with anionic emulsifiers. The amount of emulsifier is generally 0.1 to 5.0 wt .-%, based on the total weight of the comonomers. Suitable nonionic emulsifiers are, for example, acyl, alkyl, oleyl and alkylaryl ethoxylates. These products are commercially available, for example, under the name Genapol ^R or Lutensol ^R. These include ethoxylated mono-, di- and tri-alkyl phenols, preferably having a degree of ethoxylation from 3 to 50 ethylene oxide units and C ₄ - to C ₂ alkyl groups; and ethoxylated fatty alcohols, preferably with a degree of ethoxylation of from 3 to 80 ethylene oxide units and C ₈ - to C ₃₆ -alkyl radicals. Suitable nonionic emulsifiers are also Ci ₃ -Ci ₅ -Oxoalkoholethoxylate with a degree of ethoxylation of 3 to 30 ethylene oxide units, C ₆ -C ₈ fatty alcohol ethoxylates having a degree of ethoxylation of 11 to 80 ethylene oxide units, Cio-oxoalcohol ethoxylates having a degree of ethoxylation of 3 to 11 ethylene oxide units, C ₃ -Oxoalkoholethoxylate with a degree of ethoxylation of 3 to 20 ethylene oxide units, Polyoxyethyl- ensorbitanmonooleat with 20 ethylene oxide groups, lenoxyd copolymers of ethylene oxide and propylene oxide having a minimum content of 10 wt .-% ethylene lenoxid, polyethylene oxide ethers of oleyl alcohol having a degree of ethoxylation of 4 to 20 ethylene oxide units and the polyethylene oxide ethers of nonylphenol having a degree of ethoxylation of 4 to 20 ethylene oxide units.

Particularly preferred are C ₂ -C ₄ -fatty alcohol ethoxylates with a

Degree of ethoxylation from 3 to 30 ethylene oxide units.

Examples of suitable anionic emulsifiers are sodium, potassium and ammonium salts of straight-chain aliphatic carboxylic acids having 12 to 20 C atoms; Sodium hydroxyoctadecane sulfonate; Sodium, potassium and ammonium salts of hydroxy fatty acids having 12 to 20 carbon atoms and their sulfonation and / or acetylation products; Sodium, potassium and ammonium salts of alkyl sulfates, also known as triethanolamine salts, and sodium, potassium and ammonium salts of alkyl sulfonates each having 10 to 20 carbon atoms and alkylaryl sulfonates having 12 to 20 carbon atoms; Dimethyl-dialkylammonium chloride having 8 to 18 C atoms in the alkyl radical and their sulfonation products; Sodium, potassium and ammonium salts of sulfosuccinic acid esters with aliphatic saturated monohydric alcohols having 4 to 16 carbon atoms and of sulfosuccinic acid 4-esters with polyethylene glycol ethers of monohydric aliphatic alcohols having 10 to 12 carbon atoms, especially their di-sodium salts; Sodium, potassium and ammonium salts of sulfosuccinic acid 4-esters with polyethylene glycol nonylphenyl ether, especially its di-sodium salt; Sodium, potassium and ammonium salts of sulfosuccinic acid bis-cyclohexyl ester, especially its sodium salt; Lignosulfonic acid and its calcium, magnesium, sodium and ammonium salts; Resin acids and hydrogenated and dehydrated resin acids and their alkali metal salts.

In the preparation of the aqueous dispersion of the vinyl acetate polymer, no emulsifiers are preferably used during the polymerization, and no emulsifiers are added subsequently. The polymerization is generally carried out in each case to a conversion of> 95 wt .-%, preferably up to a conversion of 95 to 99% by weight, of the liquid monomers under polymerization.

The aqueous dispersions of the vinyl acetate polymer or the vinyl acetate-ethylene copolymer obtainable therewith in each case have a solids content of from 30 to 75% by weight, preferably from 50 to 65% by weight. Suitable aqueous dispersions of vinyl acetate polymers or of vinyl acetate-ethylene copolymers are also commercially available. For example, the Vinnapas ^R dispersions of Wacker Chemie AG.

The mixtures contain at least one aqueous dispersion of a vinyl acetate polymer and at least one aqueous dispersion of a vinyl acetate-ethylene copolymer with a weight fraction of preferably 10 to 60 wt .-%, particularly preferably 10 to 40 wt .-%, most preferably 20 to 30 wt .-% vinyl acetate polymer, in each case based on the total weight of vinyl acetate polymer and vinyl acetate-ethylene copolymer (dry / dry). The proportion by weight of the vinyl acetate polymer can vary depending on the glass transition temperature Tg of the vinyl acetate-ethylene copolymer. The lower the Tg, the higher the proportion of the vinyl acetate polymer can be selected.

Another object of the invention are carpet coating compositions prepared from

a mixture comprising an aqueous dispersion of a vinyl acetate polymer and an aqueous dispersion of a vinyl acetate-ethylene copolymer,

100 to 1400% by weight of fillers, based on the weight of the mixture of vinyl acetate polymer and vinyl acetate-ethylene copolymer (dry / dry),

Water,

optionally one or more additives and optionally one or more additives. The solids content of the carpet coating compositions is preferably from 72 to 83% by weight, more preferably from 75 to 80% by weight, based in each case on the total weight of the carpet coating compositions. The carpet coating compositions, after addition of fillers and in the absence of additives or additives, have a Brookfield viscosity of preferably <7000 raPas, more preferably <3000 mPas (measured with Brookfield RV gauge with spindle 4, 20 rpm, at 25 ° C). Suitable fillers are, for example, kaolin, talc, fluorspar, fly ash, aluminum trihydrate, preferably chalk.

Examples of additives are thickeners, such as polyacrylates or cellulose ethers, or foam auxiliaries. In the case of foam application foam assistants are preferably added. Thickeners may be added to adjust the target viscosity of the carpet coating compositions. In general, an amount of thickener ranging from 0.1 to 6 wt .-%, and preferably 1 to 3 wt .-%, each based on the weight of the mixture of vinyl acetate polymer and vinyl acetate-ethylene copolymer (dry / sufficient) dry). Preferably, a Brookfield viscosity of 2000 to 10,000 mPas is set in this way (measurement with Brookfield RV meter with spindle 4, 20 rpm, at 25 ° C). In the procedure according to the invention, however, thickening agents can also be used.

Typical additives are, for example, dispersants, wetting agents, pigments, water repellents or biocides, such as formaldehyde depot substances, isothiazolinones, phenols or quaternary ammonium compounds. The carpet coating compositions preferably contain no plasticizers or film-forming aids.

The carpet coating compositions contain from 100 to 1400 parts by weight of filler per 100 parts of the mixture of vinyl acetate polymer and vinyl acetate-ethylene copolymer (dry / dry) This is also referred to as a fill level of 100% to 1400%. The amount of fillers in the formulation may vary depending on the desired coating properties. The higher the proportion of filler (degree of filling), the lower the mechanical properties.

The carpet coating compositions of the invention are characterized by a high filler compatibility. Thus, carpet coating compositions are obtainable, for example consisting of polymer dispersion, fillers and water, which at fillages of 400 wt .-% to 1400 wt .-% filler, based on the mixture of vinyl acetate polymer and vinyl acetate-ethylene copolymer ( dry / dry), and at a solids content of 75 to 85 wt .-%, a Brookfield viscosity of <7000 mPas and particularly preferably of <3000 mPa s have (measurement with Brookfield RV meter with spindle 4, 20 rpm, at 25 ° C).

If the viscosity of a carpet coating composition is higher prior to the addition of the thickener, the incorporation times for the filler will be longer, which is generally unacceptable on an industrial scale, and there is a danger of forming nondispersed filler lumps which can damage the carpet fabric. Carpet coating compositions with fill levels of 300% to 1400% are preferably used for the precoat. Fill levels of from 600% to 1000% are preferred for home coats and from 300% to 600% for commercial applications such as office, hotel or ships.

For the second line, carpet coating compositions with fill levels of 275% to 600% for residential applications and 200% to 275% for commercial applications such as office, hotel or ships are preferably used. To prepare the carpet coating compositions, it is possible to proceed by mixing the aqueous dispersion of the vinyl acetate polymer and the aqueous dispersion of the vinyl acetate-ethylene copolymer and then stirring in the fillers. Any additives and additives may generally be added at any time, preferably before the addition of fillers. For the preparation of the carpet coating compositions, the equipment established for this purpose and known to the person skilled in the art is suitable.

Another object of the invention are carpets which are coated with one or more inventive carpet coating compositions in the precoat and / or second coat. The carpet coating compositions may be advantageously employed by known methods in existing carpet making facilities.

The carpet coating compositions are suitable for the curing of carpets, for example, woven or carpet tiles.

The carpet coating compositions can be used to make tufted carpets, woven carpets or needle felt carpets. The following examples serve to further explain the invention:

Methods: Determination of the glass transition temperature Tg:

The glass transition temperature Tg of the polymers was determined by means of DSC (Dynamic Differential Thermal Analysis, DIN EN ISO 11357-1 / 2) with the dynamic differential calorimeter DSC 1 from Mettler-Toledo in an open crucible at a heating rate of 10 K / min. As a glass Transition temperature was evaluated, the temperature at the midpoint of the second heating curve (center = half step height).

Determination of Brookfield viscosity:

The determination of the Brookfield viscosities of the aqueous polymer dispersions was carried out with a Brookfield RV viscometer, after tempering to the specified temperature, using the specified spindle, at the specified number of revolutions per minute. The viscosity is given in mPas.

Determination of particle size Dw:

Mean particle diameter Dw determined with the Beckmann Coulter® LS measuring instrument according to ISO 13320. Examples:

Dispersion A (A)

The following components were prepared in a nitrogen-purged 572-

Liter pressure reactor submitted:

125.2 kg of deionized water,

56.0 kg of a 20% strength by weight aqueous solution of a polyvinyl alcohol having an average degree of hydrolysis of 88 mol% and a Höppler viscosity of 4 mPas (determined to DIN 53015, at 20 ° C., in 4

% aqueous solution),

26.1 kg of a 25% strength by weight aqueous solution of a fatty alcohol ethoxylate having a mean degree of ethoxylation of 30 mol

EO units,

241.7 kg vinyl acetate,

0.48 kg of a 1.0 wt .-% aqueous ammonium sulfate solution.

The original was adjusted to a pH of 4.0 with 250 ml of formic acid (98% strength by weight).

With stirring (240 rpm), the template was heated to 35 ° C and ethylene was pressed to a pressure of 30 bar. Upon reaching the temperature of 35 ° C and a pressure of 30 bar, the initial tordosierungen, consisting of an aqueous 3.5 wt .-% - hydrogen peroxide solution and an aqueous 10 wt .-% sodium I so ascorbate solution, started at 700 g / h. After the start of the reaction (10 minutes after initiator dosing), clearly indicated by the increase in the internal temperature of the reactor, the internal temperature of the reactor was raised to 85.degree. C. with the aid of the released heat of reaction. In parallel, 10 minutes after the start of the reaction, a vinyl acetate metering was started at 35.1 kg / h (dosing time 120 min, 70.2 kg). Upon reaching a reactor internal temperature of 80 ° C, ethylene was followed up to a target pressure of 58 bar until a total amount of ethylene of 52.8 kg was metered.

After the end of the vinyl acetate doses, the initiator doses were further metered in at 2000 g / h for a further 30 minutes, the pressure dropping to 20 bar. The mixture was then cooled to 70 ° C and transferred to a pressureless reactor (low pressure reactor) and abs there at a pressure of 700 mbar. by addition of 2.6 kg tert. Butylhydroperoxide solution (10 wt .-% in water) and 2.6 kg sodium isoascorbate solution (10 wt .-% in water) postpolymerized.

Solid content: 63% by weight

Brookfield viscosity: 1300 mPas (spindle 2, 20 rpm, 23 ° C.)

Particle size: Dw 1.0 μιτι, (Coulter LS)

Glass transition temperature: 7.0 ° C (DSC)

Protective colloid: 3.1% by weight, based on comonomers

Emulsifier: 1.8% by weight, based on comonomers

Dispersion B (B)

An aqueous dispersion of a vinyl acetate homopolymer having a glass transition temperature of 33 ° C and having a solids content of the dispersion of 55 wt .-%, stabilized with 6 wt .-% of a Polyvi- nylalkohols having a mean degree of hydrolysis of 88 mol% and a Hoppler Viscosity of 5 mPas (determined according to DIN 53015, at 20 ° C, in 4% aqueous solution), and 2.0 wt .-% of a polyvinyl alcohol having an average degree of hydrolysis of 88 mol% and a Höppler viscosity of 50 mPas (determined according to DIN 53015, at 20 ° C, in 4% ^- iger aqueous solution), wherein the data in wt .-% are each based on the vinyl acetate homopolymer.

Dispersion D (D)

As dispersion B (vinyl acetate homopolymer dispersion, Tg = 33 ° C, FG = 55%) but with 7.0 wt .-% of a polyvinyl alcohol having an average degree of hydrolysis of 88 mol% and a Hoppler viscosity of 4 mPas (determined according to DIN 53015, at 20 ° C., in 4% strength aqueous solution), the data in% by weight being based in each case on the vinyl acetate homopolymer.

Dispersion E (E)

The following components were placed in a nitrogen-purged 590 liter pressure reactor:

134.9 kg of deionized water,

75.9 kg of a 20 wt .-% - aqueous solution of a polyvinyl alcohol having an average degree of hydrolysis of 88 mol% and a Hoppler viscosity of 4 mPas (determined according to DIN 53015, at 20 ° C, in 4% aqueous Solution),

12.5 kg of a 10% strength by weight aqueous solution of a polyvinyl alcohol having an average degree of hydrolysis of 88 mol% and a Hoppler viscosity of 23-26 mPas (determined to DIN 53015, at 20 ° C., in 4% aqueous solution),

224 kg of vinyl acetate,

0.48 kg of a 1.0 wt .-% aqueous ammonium sulfate solution.

With stirring (240 rpm), the original was heated to 55 ° C and ethylene was pressed to a pressure of 20 bar. Upon reaching the temperature of 55 ° C. and a pressure of 20 bar, the initiator doses consisting of an aqueous 3% by weight tert-butyl hydroperoxide solution and an aqueous 5% strength by weight ascorbic acid solution, started at 700 g / h each. After the start of the reaction, clearly recognizable by the increase in the internal temperature of the reactor, the Reactor internal temperature with the aid of the released heat of reaction to 90 ° C and the pressure raised to 48 bar. The initiator doses were each reduced to 350 g / h to control the heat of reaction.

45 minutes after the start of the reaction, a vinyl acetate and a polyvinyl alcohol dosage were started. Vinyl acetate was metered into the reactor within 90 minutes at a rate of 40 kg / h (= 60 kg of vinyl acetate), the polyvinyl alcohol consisting of a 10% by weight aqueous solution of a polyvinyl alcohol having an average degree of hydrolysis of 88 mol%. % and a Höppler viscosity of 4 mPas

(Determination to DIN 53015, at 20 ° C, in 4% aqueous solution), was within 120 minutes at a rate of 14 kg / h (= 28.0 kg of aqueous polyvinyl alcohol solution). Ethylene was metered in during the polymerization at a nominal pressure of 44 bar until a total amount of ethylene of 34 kg had been metered.

After the doses had ended, the initiator doses were further metered in at a rate of 1300 g / h for a further 30 minutes, the pressure dropping to 20 bar. Subsequently, the batch was cooled to 65 ° C and transferred to a pressureless reactor (low pressure reactor) and abs there at a pressure of 700 mbar. by addition of 1 kg of tert. Butyl hydroperoxide solution (10 wt .-% in water) and 2 kg of ascorbic acid solution (5 wt .-% in water) postpolymerized.

Solid content: 58% by weight

Brookfield viscosity: 1800 mPas (spindle 2, 20 rpm, 23 ° C)

Particle size: Dw 1.0 μιτι, (Coulter LS)

Glass transition temperature: 15.0 ° C (DSC)

Protective colloid: 6.2% by weight, based on comonomers

Dispersion C (C)

Like dispersion E but with the following monomer ratio:

77% by weight of vinyl acetate and 23% by weight of ethylene.

Solid content: 54% by weight

Brookfield viscosity: 280 mPas (spindle 1, 20 rpm, 23 ° C)

Particle size: Dw 1.0 μιτι, (Coulter LS)

Glass transition temperature: -6.0 ° C (DSC) Protective colloid: 6.3% by weight, based on comonomers Comparative dispersion 1 (VI)

Styrene butadiene latex DL 535 (DOW Chemical Company)

Fixed content: 49.5 - 50.5%

Brookfield viscosity: max. 300 mPas (spindle 2, 50 rpm, 23 ° C)

Glass transition temperature: 15 ° C

Styrene content in polymer: 60.5% comparative dispersion 2 (V2)

Styrene-butadiene latex DL 521M (DOW Chemical Company)

Fixed content: 51.5 - 52.5%

Brookfield viscosity: 100-300 mPas (spindle 2, 50 rpm, 23 ° C.)

Glass transition temperature: 6.0 ° C

Styrene content in polymer: 63%

Comparative dispersion 3 (V3)

Styrene-butadiene latex XZ 92227.01 (DOW Chemical Company)

Fixed content: 50.5 - 51.5%

Brookfield viscosity: 50-350 mPas (spindle 2, 50 rpm, 23 ° C.)

Glass transition temperature: -15.0 ° C

Preparation of the Carpet Coating Compositions: With the dispersions A to E and the comparative dispersions V 1 to V 3 and blends thereof, carpet coating compositions were prepared based on the following recipe:

100 parts by weight of the respective dispersion or mixture

(Polymer dry),

450 parts by weight of chalk (Carbocia 80, Carbocia) (filler),

0.5 part by weight of foam aid (sodium lauryl sulfate).

The parts in parts by weight are based on the dry weight of the respective carpet coating composition. Additional water was added in an amount to result in carpet coating compositions having a solids content of 81.5% by weight. In the case of mixtures of styrene-butadiene copolymers and vinyl acetate homopolymers, water was added until the target viscosity of 6000 to 7000 mPas was reached (measurement with Brookfield RV meter with spindle 4, 20 rpm, at 25 ° C.).

To prepare the carpet coating compositions, the water and the respective dispersion or dispersion mixture were initially introduced, and with stirring the filler and then the foam aid were added.

The carpet coating compositions had a solids content of 81.5 wt% and a fill level of 450 wt%.

Subsequently, a final viscosity of 6500 mPas was set by addition of a thickening agent (acrylate thickener Matco TR 10, Matco) (measurement with Brookfield RV gauge with spindle 4, 20 rpm, at 25 ° C.).

In general, final viscosities of 6,000 to 7,000 mPas are acceptable.

Production of carpets:

The respective carpet coating composition described above was foamed for 3 minutes with a food processor, so that

Foam liter weights of 950 to 1015 g / L were achieved.

As a precoat, 148 g of the respective foamed carpet-coating composition were evenly distributed on a 38 cm X 33 cm Tuftrohteppich (Schlingenpol tufted carpet, 100% polyamide, 550 g / m ² pole weight, quality Helsinki, manufacturer: Edel).

Then 60 g of the respective foamed carpet coating composition were applied as a second coat and uniform distributed. Then a textile back (polypropylene fabric, Action Back) was placed and worked twice with a 1.6 kg roll without pressure. It was dried for 20 minutes at 130 ° C in an oven.

Measurement of dimpled pull-out force:

The nubs extraction force was tested according to ISO 4919 using a Zwick testing machine at 23 ° C and 50% relative humidity. The respective carpet was clamped in the attachment at the bottom of the meter and threaded a needle in a carpet loop. Ten different carpet loops were used to determine the force required to pull a loop out of the carpet. The mean value of the results of the measurements gave the dry nub extracting power.

To determine the wet nub extraction force, samples prepared for the determination of the dry nub draw force were placed in water for 10 minutes, blotted dry on the surface before further testing and thus freed from excess water

The dry dimpled pull-out force and the wet dimpled pull-out force are a measure of the quality of the dimpled bond provided by the precoat and the abrasive properties of the carpet surface. Therefore, they should be as high as possible.

Measurement of the separation strength:

The release strength was determined analogously to DIN EN ISO 11857 with the aid of a Zwick testing machine at 23 ° C. and 50% relative atmospheric humidity. Three samples were made by cutting 5 cm wide, 20 cm long strips from the respective carpet in the machine direction and separating them by hand on the narrow side over a length of 5 cm. Each separated sample was clamped in a Zwick testing machine and at a speed of severity of 300 mm / min of the secondary backs separated from the carpet. The total mean of five samples was determined according to DIN EN ISO 11857 from the mean values of the peak values per sample in the permissible measuring range. The first 25% of the respective measurement curve was marked and not taken into account for the evaluation. The next 50% of the graph chart was divided into 5 equal sections and from these the respective peak value was determined. The peak values were summarized by the mean and the mean values in turn to the total mean. The release strength was given in Newton [N].

To determine the wet separation strength, samples prepared in order to determine the dry separation strength were additionally immersed in water for 10 minutes and blotted dry on the surface before further testing and thus freed of supernatant water.

Measurement of the bending resistance of filled polymer films:

To evaluate the flexural resistance properties of filled polymer films as a measure of the flexibility of the finished carpet, the previously described formulations were used for carpet coating compositions.

The carpet coating compositions were coated with a doctor blade onto a glass sheet to give a layer thickness of 2 mm. The pre-drying of the filled polymer films was carried out at 23 ° C and 50% relative humidity for 24 hours. Before the further treatment, 5 test specimens in the dimensions 38 mm × 50 mm were punched out per carpet coating composition.

The thus prepared and predried test specimens were then thermally post-treated in the drying oven at 130 ° C. for 20 minutes, in the same way as the carpets equipped with the corresponding carpet coating composition, and after cooling for 1 hour under standard conditions (23 ° C. and 50% relative atmospheric humidity). Gela siege. After final storage, the flexural resistance was measured in mN according to SCAN P 29:95 (NORM).

The test specimens were subsequently clamped in the device (L & W Bending Resistance Tester SE 016) and measured at a bending angle of 15 ° with a measuring length of 25 mm. The maximum bending resistance was determined as the force in mN that occurs when the sample is deflected at a constant angular velocity at a preselected measuring length. The results thus obtained were converted into raN / rara by dividing by the film thickness into a specific bending resistance to correct differences in the film thicknesses of the measured films. The film thickness was determined by m-meter at 5 points and the average was formed. Example 1 :

In Table 1, the results from measurements of the mechanical properties of finished carpets, prepared from binder mixtures of the dispersions A (Tg 7 ° C, mixed stabilized) and B (Tg 33 ° C) are described.

The separation strengths and dimple extraction forces from the mechanical tests can be summarized in a sum parameter, which summarizes the combined properties of the mechanical test and minimizes possible operator effects. The sum parameter also gives information about the performance of the dispersion mixtures in comparison to the non-mixed dispersions. If the sum value of the mixture is higher than the values of the original dispersions, a strengthening effect can be assumed.

Examples IA to IE show the adjustability of the specific flexural resistance of the filled film as an indicator of the finished carpet through the choice of the blend ratio of vinyl acetate-ethylene copolymer dispersion and vinyl acetate homopolymer dispersion. The bending resistance is generally better with the mixtures than with formulations containing only one dispersion. This also applies to the dimple extraction force, which is generally better with the mixtures. Furthermore, a mixing ratio of 40 wt .-% VAE dispersion and 60 wt .-% VAc dispersion (Example 1. D) shows a higher sum parameter than the dispersions used individually.

Table 1 Test Results Mixtures of Dispersions A and B.

Example 1 TrennNoppenSummen- Biege ^¬

Disp. A Disp. B tensile strength parameter resistance * dry dry

% By weight [N] [N] [N] [mN / mm]

1 . A 100 0 44.4 31.4 75, 8 678

1 .B 90 10 38.3 37, 4 75.7 1260

1 .C 70 30 39, 7 42, 3 82, 0 2728

1 .D 40 60 56, 9 34, 2 91, 1 4304

1 .E 0 100 59, 6 28, 6 88.2 X

* Bending resistance indicated by X could not be measured because of too high rigidity. The corresponding carpets showed no flexibility and bending of the back coating on bending.

Example 2: Combinations of a Polyvinyl Alcohol-Stabilized Vinyl Acetate

Ethylene copolymer dispersion (Disp C) with a low Tg of -6 ° C and a polyvinyl alcohol-stabilized vinyl acetate homopolymer dispersion (Disp D) showed similar performance in terms of flexibility of finished carpets and mechanical test data. Particularly noteworthy are in addition to the surprisingly easy adjustability of the carpet flexibility over a wide range of mixing ratios of the dispersions and the unexpectedly high strengths after water treatment. Again, the results of the separation strength and Noppenauszugsuntersuchung be summarized to a sum parameter that allows a better evaluation of the overall performance. The results for the mixtures are in Examples 2.B to 2.F, in particular after water treatment, better than the results of the individual dispersions.

Table 2 Test results Mixtures of dispersions C and D.

Separating dimpled

Example 2 bending sum parameter

Wider¬

Disp. Disp. dry wet dry stand * dry wet C D en

Gew. - wt. -

[N] [N] [N] [N] [mN / mm] [N] [N]

, A 100 0 58.5 20, 1 28.5 13.4 989 87 33, 6

.B 90 10 65 21.2 23, 1 12, 6 1818 88, 1 33, 8

.C 80 20 61 21.2 24.5 16, 0 2335 85, 5 37, 2

.D 70 30 59, 3 18.2 29.7 15, 8 3074 89, 0 34, 0

.E 60 40 58 21.2 23, 9 18, 6 3202 81, 9 39, 8. .F 50 50 51.7 18, 6 22, 8 21, 1 3282 74.5 39, 9

.G 0 100 67, 4 12, 8 23, 55 16, 4 X 90, 9 29.2

* Bending resistances which are indicated by X, could not be measured due to high Stei ^¬ stiffness. The corresponding carpets showed no flexibility and bending of the back coating on bending. Example 3:

In Example 3, as in Example 2, mixtures of purely polyvinyl alcohol-stabilized dispersions were investigated, with the difference that the vinyl acetate-ethylene copolymer dispersion had a lower ethylene content and a glass transition temperature of

15 ° C (dispersion E). The vinyl acetate homopolymer was the low-viscosity polymer used in Example 2 (dispersion D).

Here, too, the blends in the sum parameters of the mechanical strength showed better properties than their corresponding individual dispersions. Due to the harder polymer base with already higher Tg (15 ° C) of the vinyl acetate-ethylene copolymer, the limit of the measurable bending resistance was already achieved in the blend in Example 3.C. Table 3 Test Results Mixtures Dispersions E and D

TrennNoppenSummen-

Example 3 Bending Strength Ability to perform parametei

Contrary-

Disp. Disp.

dry dry stand * dry E D

Ex. % By weight [N] [N] [mN / mm] [N]

3. A 100 0 69, 1 28, 8 1853 98, 0

3.B 90 10 63, 6 37, 6 2950 101.3

3.C 70 30 65, 0 33, 8 4472 98, 8

3.D 40 60 65, 3 24.4 X 89, 8

3.E 0 100 67, 4 23.5 X 91, 0

* Bending resistances which are indicated by X, could not be measured due to high Stei ^¬ stiffness. The corresponding carpets showed no flexibility and bending of the back coating on bending.

Example 4

Blends of the hard vinyl acetate-ethylene dispersion from Example 3 (Tg = 15 ° C., dispersion E) with a higher-viscosity homopolymer dispersion based on vinyl acetate (dispersion B) showed in the results of the mechanical test for example 4.B already with only 10% homopolymer dispersion significantly better values than the individual dispersions. Table 4 Test Results Mixtures Dispersions E and B,

TrennBiege ^¬

NoppenSummen¬

Example 4 was festig ^¬ resist output power parameters ness

Disp. Disp.

Dry dry dry

E B

Gew. - wt. -

Ex. [N] [N] [mN / mm] [N]

4. A 100 0 69, 1 28, 8 1853 98, 0

4.B 90 10 67 38, 8 3743 105, 8

4.C 40 60 69, 4 30.3 X 99, 8

4.D 0 100 59, 6 28, 1 X 88.3

* Bending resistances indicated by X could not be measured due to excessive rigidity. The corresponding carpets showed no flexibility and bending of the back coating on bending. Examples 5 to 7:

In the comparative experiments of Examples 5 to 7 were in each case two ratios (each based on the solids content of the dispersion, ie polymer to polymer in wt .-% / wt .-%), 60 wt .-% to 40 wt .-% and conversely, blends with homopolymers and commercially available styrene-butadiene copolymers were prepared.

The resulting fixed salaries are summarized in Table 5 (column 3). The deviations from the target solids content of 81.5%, the solids content of the formulations of vinyl acetate-ethylene and vinyl acetate homopolymer mixtures, are sometimes considerable.

This means an immediate increase in formulation and process costs due to the higher amount of water to be evaporated. Such low fixed salaries of the formulation are therefore not commercially attractive.

The incompatibility of vinyl-vinyl-alcohol-stabilized vinyl acetate homopolymer dispersions and styrene-butadiene copolymers, as mentioned in WO 2013/123210, in the direct mixture of both dispersions becomes clear. Without the addition of emulsifiers or high dilution, a significant increase in viscosity can be recorded in these mixtures depending on the mixing ratio.

The data of the mixing viscosities are also given in Table 5. Such high viscosities are generally not processable in typical systems and can lead to long service life of system parts.

The mixtures of vinyl acetate-ethylene copolymers with vinyl acetate homopolymers, however, lead to no such viscosity increases and it can just as easily reach the target salaries of the formulation of 81.5%. Examples 8 to 10 demonstrate the compatibility of vinyl acetate-ethylene dispersions and vinyl acetate homopolymer dispersions based on viscosity data of the mixture in the same mixing ratios from Examples 5 to 7. The advantage here lies in the compatibility of both polymers and the compatibility of the stabilization systems. In addition, as already shown in Examples 1 to 4, further positive effects, such as the adjustment of the flexibility and the improvement of the mechanical properties, are associated with the mixtures according to the invention.

Table 5 Summary of Viscosities of Disperisone Blends.

Examples 5-10 Ratio of Viscosity

Mixtures solid content mixture

SB / VAc VAE / VAc

Dispersions Formulation Dispersions

Ex. Disp. / Disp. % By weight% by weight [mPa s]

5 Vl / B 75, 8 60/40 129000

6 V2 / B 77.6 60/40 150000

7 V3 / B 72, 6 60/40 70000

8 A / B 81.5 60/40 3330

9 C / D 81.5 60/40 358

10 E / B 81.5 60/40 3780

By SB / VAc ratio is meant the blending ratios of the dispersions in columns 3 and 4 based on the solids content of the particular dispersion. SB: styrene-butadiene dispersion, VAc: vinyl acetate homopolymer dispersion

Claims

Use of mixtures comprising an aqueous dispersion of a vinyl acetate polymer and an aqueous dispersion of a vinyl acetate-ethylene copolymer for carpet coating compositions.

Use according to claim 1, characterized in that the vinyl acetate polymer by means of free-radically initiated emulsion polymerization in an aqueous medium from 99 to 100 wt .-% vinyl acetate and optionally up to 1 wt .-% of other comonomers re, each based on the total weight of the monomers, the data in% by weight being in each case 100% by weight. add up.

Use according to claim 1 or 2, characterized in that the vinyl acetate-ethylene copolymer by means of free-radically initiated emulsion polymerization in an aqueous medium of 65 to 98 wt .-% vinyl acetate and 2 to 30 wt .-% of ethylene, and optionally up to 10 wt. % of further comonomers, in each case based on the total weight of the monomers, is obtained, the data in% by weight being in each case 100% by weight. add up.

Use according to claim 1 or 2, characterized in that the polymerization of the vinyl acetate polymer is carried out in the presence of protective colloid, optionally in combination with emulsifier.

Use according to claim 1 or 3, characterized in that the polymerization of the vinyl acetate-ethylene copolymer takes place in the presence of protective colloid or in the presence of emulsifier or in the presence of a combination of protective colloid and emulsifier. Use according to claim 4 or 5, characterized in that both the polymerization of the vinyl acetate polymer and the polymerization of the vinyl acetate-ethylene copolymer in the presence of partially saponified polyvinyl alcohol having a degree of hydrolysis of 80 to 95 mol% and a Höppler viscosity in 4%. iger aqueous solution of 1 to 40 mPas (method according to Hoppler at 20 ° C, DIN 53015) takes place.

Use according to claim 1 to 6, characterized in that the mixtures at least one aqueous dispersion of a vinyl acetate polymer and at least one aqueous dispersion of a vinyl acetate-ethylene copolymer having a weight fraction of from 10 to 60 wt .-% vinyl acetate polymer, in each case on the total weight of vinyl acetate polymer and vinyl acetate-ethylene copolymer (dry / dry).

Carpet coating compositions prepared from a mixture containing an aqueous dispersion of a vinyl acetate polymer and an aqueous dispersion of a vinyl acetate-ethylene copolymer, and 100 to 1400 wt .-% fillers, based on the weight of the mixture of vinyl acetate polymer and vinyl acetate-ethylene Copolymer (dry / dry), and water, and optionally one or more additives and optionally one or more additives.

A carpet coating composition according to claim 8, characterized in that the mixture of the aqueous dispersions and the filler, before the addition of additives and additives, at a solids content of 75 to 85 wt .-% of a

Brookfield viscosity of <7000 mPas.

Carpets which are coated with one or more carpet coating compositions according to claim 8 or 9 in the pre-coat and / or second coat.